You got it!
The 38"s leave just enough crud, (bullet lube, powder residue, ect.) to make chambering difficult. One of those RCBS handles that you can screw a cleaning brush into is really handy for quick scrub's.
On the crimp, just back it off maybe about a 1/4 turn and try it. Also check if your brass doesnt have a sharp edge on it (not chamfered) that can cause a little ring also. It doesn't really hurt anything but can get caught up in the dies and gun.